Page 313 - My FlipBook

CONSTRUCTION AND PLACING OF PORCELAIN INLAY 309

cervix and pronouncedly blue at the incisal edge are best repre-
sented by building in sections provided; the cavity involves both
regions spoken of as in Class Four (proximo-incisal).
After the different sections have been applied and brought to a
hard biscuit fuse, a uniform layer of neutral color is applied over
the whole and all fully fused.
Applying the Porcelain to the Matrix. The foundation body is
put upon the porcelain or glass slab and sufficient distilled water,
or alcohol or a mixture of both, added to make a stiff paste, stiff
enough to retain its shape when taken up on the point of a spatula.
A small quantity of this is laid in the bottom of the matrix and
by a little jolting made to flow over the surface. This jolting is
best produced by drawing the edge of a fine gold file over the
tweezers holding the matrix. The additions should be continued
until sufficient body has been added. Excess moisture is removed
by repeated jolting and absorbing with blotting paper. Dark col-
ored blotting paper is used so as to detect any paper fibers Avhich
by accident adhere, which should be removed. The addition of
dry porcelain of the same color will take up the excess moisture,
the surplus adhering poAvder being brushed off with a small brush.
In Case the Matrix is Tom, the opening has to be comparatively
large to cause the porcelain to run through, unless the matrix is
damp on the cavity side or too moist a mix is being applied.
Should any of the porcelain flow through, it can be removed with
a dry brush provided the porcelain has been rendered quite dry.
Do not apply a wet brush to the cavity side of the matrix. The
inlay should now be placed in the oven and fused sufficiently to
produce the greater part of the shrinkage, but not to a full gloss.
When removed from the oven if more foundation is needed it
should be added and fired to a high biscuit.
The Enamel in Proper Shades is now added, either in layers or
sections, and again fired to a high biscuit. The inlay should then
be tried into the cavity for bulk and contour. If not correct more
enamel is added. When the contour suits, the inlay is replaced in
the oven and fired to a full glaze. The skill necessary to reproduce
the colors of the teeth comes Avith practice and the longer one en-
gages in this Avork the more often Avill the results please the oper-
ator,
Technic of Fusing* Porcelain. The furnace should be firet heated
up to a bright red and held there for a minute or tAvo, to thor-